Improvement in furnace-doors



UNITED STATES PATENT OEEIOE.

JOHN MORRISON, OF PITTSBURG, PENNSYLVANIA.

IMPROVEMENT IN FURNACE-DOORS.

Specification forming part of Letters Patent No. 208,415, dated September 24, ISTS; application filed January 29, 1878.

To all whom it may concern Be it known that I, JOHN MORRISON, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Furnace- Doors; and l do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilledin the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of ret'ereuce marked thereon, which forni a part of this specification.

Figure l is a perspective view. Fig. 2 is a vertical transverse section. Fig. 3 is a longitudinal vertical section, and Fig. 4 is a horizontal section of the door.

My invention has reference to the construction of doors for metallurgie furnaces, particularly of that class known as heating-furhaces;77 and it consists in making the door of one or more blocks of nre-clay or other refractory material, so fitted to aframe-work as to form the entire front and rear faces of the door, whereby the latter is rendered reversible.

It also consists in the particulars of construction, combination, and arrangement hereinafter fully described and claimed.

In the accompanying drawings, A B O designate oblon g blocks of iire-clay-their length being equal to the width of the door--grooved on their exterior edges,`and jointed together by tongue and groove, as shown in sectional views. These blocks are set into aframe consisting of the top and bottom bars, D D', having on their inner faces the longitudinal ribs d d', which lit into the blocks A O.

The side bars, E, lie in the end grooves of the blocks A B C, and secure the bar D by a rabbeted head, e, fitting a recess in the bar D', and the whole is firmly secured together by the nuts f or equivalent fastening.

1f the door be of unusual width, a central upright, g, running through the blocks, may be used to give stiffness to the whole, or a similar tie-rod may be passed through horizontally, to keep Vthe uprights from bowing outwardly and binding the door in its frame.

rIhe advantages of this construction of door are chiefly as follows: When the interior heat has burned away the bricks to such extent as to interfere with the working of the furnace, the whole door can be reversed-both faces beingalike-so as to present the unburned face inwardly. This feature of the improvement about doubles the life of the door. Again, after such reversal, when the second face becomes burned away, since the burning only takes place on the lower half of the door, it an easy matter to take out the lower, or lower and middle, blocks, and replace them by new ones, leaving the ripper block or blocks in the frame, and thus economizing in material.

As the two faces of the door are the parts most liable to injury from heat, and as the side bars are somewhat concealed in the edges of the blocks, the metal frame is not much exposed to injury. lf the door be a square onethe form usually adopted-besides reversing, it may be reused by shifting the blocks so as to cause them to lie at right angles to their original positions, or they may be inverted.

rlhe side bars of the frame may, if desired, pass through holes `made near the ends of the blocks.

Another advantage resulting from the construction above described is a lessening of the liability to expansion, the door being made of non-expansible material, while those in cornmon use are made chieliy of iron.

Having described my invention, I claiml. A furnace-door having both inner and outer faces of lire-clay, whereby either face ot' the door, or each face in succession, may be used next the lire, as described.

2. VThe combination of the blocks A B C, having their faces forming the faces of the door, with the side bars, E, and top and bottom bars, D D', of the frame, substantially as set forth.

In testimony that I claim the foregoing as my own I aflix my signature in presence of tw witnesses. f

JOHN MORRISON.

lVit-nesses Crois. O. LEAN, F. J. McTrenE. 

